Added Texas R-PUSON-N8 package

Datasheet: https://www.ti.com/lit/gpn/tpd3f303

Source: kicad-footprint-generator!944 (merged)

I added the package and EP dimensions in the name, because EP size seems device dependant and it's not specified in the package drawing.

https://www.ti.com/lit/ml/mpss037/mpss037.pdf